Resolution of syringomyelia and Chiari I malformation by ventriculoatrial shunting in a patient with pseudotumor cerebri and a lumboperitoneal shunt.

A sneeze caused acute left arm pain in a 36-year-old woman with a lumboperitoneal (LP) shunt that had been placed 3 years earlier for relief of headaches caused by pseudotumor cerebri. Numbness progressed up the left arm, neck, and back of the head and finally into the left face along with weakness of the hand and arm. Magnetic resonance imaging (MRI) and computed tomography revealed new tonsillar herniation and a large eccentric syrinx extending from C2 to T6. The functioning LP shunt was clamped, and a ventriculoatrial shunt was placed. Pain lessened and motor function improved slightly. MRI revealed complete resolution of the syrinx and resolution of the tonsillar herniation. Theories of syringomyelia formation, the relationship to Chiari I malformation, and the implications of this case are discussed.